1. Field of the Invention
The invention relates generally to the field of photography, and more particularly to a film take-up spool in a camera.
2. Description of the Prior Art
Numerous film take-up spools have been designed to automatically engage the leader of a 35 mm filmstrip in a camera during the film loading cycle of the camera. For example, commonly assigned U.S. Pat. No. 4,303,325 issued Dec. 1, 1981 discloses a film take-up spool adapted for use with a film leader which has a connecting aperture that includes a flexible tongue element extending forward into the aperture. The take-up spool is provided with several film capturing members evenly spaced about a reduced-diameter portion of the spool core. Each of the capturing members comprises a triangular-shaped head surface, a slanted leading edge surface, and a trailing edge surface having a recess. The slanted leading edge surface engages the film leader at its capturing aperture by entering the aperture during rotation of the take-up spool in a film winding direction, and the triangular-shaped head surface then flexes the tongue element of the aperture sufficiently to allow the head surface to pass through the plane of the film leader. Further rotation of the take-up spool in the same direction allows the tongue element to snap back into the recess in the trailing edge surface to secure the leader to the reduced-diameter core portion. The head surfaces of the capturing members appear to radially extend outward to respective positions radially inward of the film supporting surface of a full-diameter portion of the spool core (see Col. 4, lines 27-33, and FIG. 2 of the patent). This, it is stated, is to prevent the capturing members from contacting the sensitive portions of the film convolutions wound on the supporting surface.